Conditioning is an important step in harvesting alfalfa hay, as squeezing and bending alfalfa stems can break down the stem fibers and accelerate the drying rate of alfalfa. The quality of alfalfa hay is directly affected by the conditioning effect. The finite element method (FEM) can quantitatively analyze the interaction relationship between alfalfa and conditioning rollers, which is of great significance for improving conditioning effects and optimizing conditioning systems. The accuracy of material engineering parameters directly affects the simulation results. Due to the small diameter and thin stem wall of alfalfa, some of its material parameters are difficult to measure or have low measurement accuracy. Based on this background, this study proposed a method for calibrating the finite element parameters of thin-walled plant stems. By conducting radial tensile, shear, bending, and radial compression tests on alfalfa stems and combining with the constitutive relationship of the material, the range of engineering parameters for the stems was preliminarily obtained. By conducting a Plackett–Burman experiment, the parameters that affect the maximum shearing force of stems were determined, including Poisson’s ratio in the isotropic plane, radial elastic modulus, and the sliding friction coefficient between the alfalfa stem and steel plate. By conducting the steepest ascent experiment and Box–Behnken experiment, the optimal values of Poisson’s ratio, radial elastic modulus, and sliding friction coefficient were obtained to be 0.42, 28.66 MPa, and 0.60, respectively. Finally, the double-shear experiment, radial compression experiment, and conditioning experiment were used to evaluate the accuracy of the parameters. The results showed that the average relative error between the maximum shear and the measured value was 0.88%, and the average relative error between the maximum radial contact force and the measured value was 2.13%. In the conditioning experiment, the load curve showed the same trend as the measured curve, and the simulation results could demonstrate the stress process and failure mode of alfalfa stems. The modeling and calibration method can effectively predict the stress and failure of alfalfa during conditioning.

Clamping is the key factor that restricts the full-process mechanization of directional shrimp peeling. To solve the problem of difficult clamping caused by the uncertainty of shrimp position after orientation, a segmented shrimp clamping method was proposed by analyzing the relationship between shrimp conveying and clamping conditions. The contact force relationship on the shrimp meat was deduced based on mechanical analysis of the clamping process, and it was concluded that the number of segmented clamping units should be increased during the clamping process to reduce the pressure of the clamping units on the shrimp meat. A segmented shrimp clamping mechanism was designed for adaptive shrimp clamping, conveying and discharging. The profile curve model of the clamping surface was built by analyzing the shrimp section profile characteristics. According to ADAMS kinematics simulation analysis, no shrimp fell off or was damaged during the clamping process, which verified the design rationality of the segmented shrimp clamping mechanism. According to the single-factor test on a newly built shrimp clamping test bench, the optimal rotation speed range of the segmented clamping mechanism was found to be 10–20 r/min, the clamping success rate was over 92%, and the shrimp integrity rate was no less than 99%. The comparison test and performance test results showed that the segmented clamping mechanism had stronger adaptability and better clamping effect under the condition of variable interval feeding. Therefore, the segmented clamping mechanism is capable of practical application and can create stable clamping conditions for shrimp peeling.